Should Discourse make an effort to become a viable comment platform?

Yes, Discourse could do something similar to that with its comment embed widget. Among other things, it might help to reduce the awkwardness that some people experience when starting a forum that only has a few active users: AI sockpuppet accounts to jumpstart my community?. New Discourse sites could use blog posts to promote and seed their forum. That is kind of possible now, but allowing users to comment directly from the embed widget would make the process more seamless.